Which Patients in the Emergency Department Should Receive Preexposure Prophylaxis? Implementation of a Predictive Analytics Approach.

Emergency Departments (EDs) have the potential to play a crucial role in HIV prevention by identifying and linking high-risk HIV-negative clients to preexposure prophylaxis (PrEP) care, but it is difficult to perform HIV risk assessment for all ED patients. We aimed to develop and implement an electronic risk score to identify ED patients who are potential candidates for PrEP. Using electronic medical record (EMR) data, we used logistic regression to model the outcome of PrEP eligibility. We converted the model into an electronic risk score and incorporated it into the EMR. The risk score is automatically calculated at triage. For patients whose risk score is above a given threshold, an automated electronic alert is sent to an HIV prevention counselor who performs real time HIV prevention counseling, risk assessment, and PrEP linkage as appropriate. The electronic risk score includes the following EMR variables: age, gender, gender of sexual partner, chief complaint, and positive test for sexually transmitted infection in the prior 6 months. A risk score ≥21 has specificity of 80.6% and sensitivity of 50%. In the first 5.5 months of implementation, the alert fired for 180 patients, 34.4% (62/180) of whom were women. Of the 51 patients who completed risk assessment, 68.6% (35/51) were interested in PrEP, 17.6% (9/51) scheduled a PrEP appointment, and 7.8% (4/51) successfully initiated PrEP. The measured number of successful PrEP initiations is likely an underestimate, as it does include patients who initiated PrEP with outside providers or referred acquaintances for PrEP care.